New Holley MPI Power Packs are partially assembled and come without an ECU, fuel injectors, wiring harness, fuel pump and sensor connectors. They are intended for the person who may want to use, or already has, different ECU components. These Power Pack kits can be used with a Holley HP or Dominator ECU or any aftermarket speed-density type ECU's that are designed for use on a multi-point system.